Flexible coupling



Dec. 14, 1954 E, R, SKLAR 2,696,719

FLEXIBLE COUPLING Filed sept. zo. 194s Gttorneg United States Patent C 21,696,719 FLEXIBLE COUPLINGy Earn-,Robert Sklar, .amden, N. j., -.,assignor,el)y,mesne .assignrnents, .to-the United -States o f -America 'as represented by ,the .Secretary rdf 4the "Navy AAppltenian;sptanimrso, 194i, 'sensi No.: 11a-'974s f4 animseinst-ars) present invention Afrgekt'tls :"to exible "coiiplings "for transmitting torque -between vdy ving'and driven :elements wlretheriin 'o1j-u't':off truealignni'ent.

4vIn certain types 'of 'servo-control mechanisms designed to Ameet specific-` iequirements wherein I a vdriven:shaft is caused lto bevrotatedbya drivershafit isunecessarfor ehi-cient and proper operation 'of the ,mechanism, to cause .the 'driv'en "shaft kto "rotate "withja In' imurn of torsional displacement or back lash with respect tojthe drive shaft. "It :would bfe dsirable to provide a rigid couplingbetweenthe driving Yand driven shaftstosatis'fy this require mentJ but ymechanical assembly will not valways-permit'thisarrangement. For "example, in4 some cases'," theaxis ofthepn `shaft'rnightbe offset with 1e' spectjto 'the axis o'f'the other'shaft, 'or'the axis of the oneesh'aft m'ig'htfb'e at an Ianglejwith respecttojthe axis of'the othershaft. O`ther cases requirejana which lwill permit 'axial movement of fthe driven shafts towardorawayffrorne hfo andrstill other case'szrriight'include a combination offthese Aseveral conditions; i

f 1` he primaryzbjeet ofniypresent inventionftherefore, is 'to' provide a exble `icoupling 'for Vconnecting driving and driven elements which "shall'transmitdriving torque betweenthe elements withk a minimum of torsional dis'- placementor backlash.

Still 'another object of my presentinvention is toproi vide a exible coupling which shall 'transmit driving torque L'from ak 'drYiUgfShft 'to a driven A shaft and yet allow `for anyjmisalignment of the'two shafts.

Afurther -obj'e'caof niv nresentinvention istopro'vide a eiiible coupling for driving `and driven shaftrnernbers which shall automatically adjust itself to' any movement of the shafts axially toward o r away from each other duringr operation 'of kthe mechanism.

lt is also anobject of:my'presentinvention to provide a exible `coupling for use with certain types of servocontrl mechanism which shall `transmit .driving torque between driving'and 'driven elements with a high-degree offelliciency.v v

JAnother 'biect-of mympreserrtinvention s to provide a exible coupling "ferr tconne'ctiiig fdriiving and driven members which employs but a few parts, and one which is simple ,and easy to construct at a minimum of sost.

Tn -accordanewith my'presentinvention, I provide a ilexble .coupling lfor'transmittin'g'torque between driving and driven shafts -which coinprises a pair of complementary coupling members each having a collar element provided with a central aperture for mounting the coupling members on their respective shafts, means being provided for adiusting and securing the coupling members to their respective shafts. A plurality of resilient, elongated coupling pins or rod-like members are mounted on one of the coupling member collars and extend therefrom in the same direction, being disposed substantially equi-angularlv about the axis of the collar and being permanently biased or loaded to be flared somewhat in relation to the collar axis. The collar of the other complementary coupling member is provided with a pluralitv of apertures for slidably receiving the resilient coupling pins. The purpose in permanently biasing or loading the resilient pins as above described, either toward or away from the axis of their associated collar central aperture, is to urge them into engagement with the walls of the resilient coupling pin receiving apertures and to minimize any torsional displacement of the shafts with respect to each other.

ICC

The novel lfeatur'es 'characteristic l of 'my invention, f as well 1 as additioakobjectsfandJ advantages t thereof, will be better understood lfrom 'the following-detailed description when "read :in 'connection with =the Iaccompan'ying' drawing'lin whichf` IFi'gure l is a sid'e'elevation vof a flexible coupling 4in accordance -with one embodiment -ofA my present invention, shown 'connecting the 'ends of ltWo-shafts the axes of which y are disposed at an f angle to t onekv another,

yFigure 2 is an endvview of `the left 'hand coupling .member of yFigure 1, which member is provided with coupling-pin receiving-apertures,

#Figure 43 =is fan end Lview 'of the 1ri'ght hand lvcoupling member of iFigure '1, fthis Vcoupling member being pro'- vided :with resilient .coupling pins `lwhich are 'biased 'to flare inwardly,

lFigure 4 is--a'sectional view takenlon theline`4-4 of Figure 3;

:Figure 5 "is anyend viewfsirnilartoFigure 3 'of arnodiedform of eouplingmernber having resilient coupling 4pins whicha'reb'iased to'flare outwardly,

yshaft and the shaft 3 is desig'nat'd'hereinas the driven shaft. vThe ilexiblecoupling v5, according tofone form of tny Ipresent '-invention, 'comprises a' pair of vcomplementary couplinginernbers 7, i9 which connectfthe driving shaft 1 with the driven shaft ASfo'r transmittingdriving torqii'e'frornone to'the other.

The Vcoupling member'7 comprises Va' vcollarll having avcentr'al aperture 1`3jfor receiving-the shaftl, fthe aperture '13 having fsubstantially'the same diameter as the diametr-'ofthelshaft '1-. 'The-collar 11 is'drilledradially and threaded to receive a set `screw '1`5 therein for the purpose of securing fthe coupling member 7 tothe shaft 1; als well as to permit adjustment of this coupling members-position on :the shaftl. A plurality of resilient coupling1p`insorjrod-like' members 1 19 are mounted on the 'collar r11, each' one havingfan'A end 17 thereof secured by suitable means tothe collar '111, with their free ends 21 -extending in theA same direction. Flfhe ,pin members 1-9 are biased -to 'converge or flare inwardly toward the artisfof tlie'aperture-'=13inf adirection away from the'collar lflan'd a'f disposed equi-angularly about thelaxis of the collar 1.1. Accordingly, when the coupling member 7 is Lsecuredgto ,"-its shaft 1,- fthe resilient coupling pin members Y"9* will 'also be eqni-'angularfly `disposed about the -shaft axis.

'The 'otherjand complementary 'coupling member 9 comprises 'a cllarZS which is similar to the collar 11, having a central aperture 27 for receiving the shaft 3, the aperture 27 having substantially the same diameter as the diameter of the shaft 3. A set screw 29 is also provided in the collar 25 for securing the coupling member 9 to the shaft 3, the set screw 29 being disposed and functioning in the same manner as the set screw 15. The collar member 2S is provided with coupling pin receiving apertures 31 which extend through the collar member 25 in spaced, substantially parallel relation to the axis of the central aperture 27. The coupling pin receiving apertures 31 are of a diameter sufficient to slidably receive the coupling pin members 19.

When assembled, the complementary coupling members 7, 9 are adjusted in position on their respective shafts so that they are spaced apart an amount suiicient to allow for any movement of the shafts axially toward or away from each other, as well as to permit exure and slidable movement of the coupling pin members 19 in the coupling pin receiving apertures 31 thereby to provide for any misalignment of the two shafts.

In operation, any torsional displacement or back lash of either shaft with respect to the other is held to a minimum because the resilient coupling pins 19 are constantly biased into contact with the walls of the coupling pin receiving apertures irrespective of the misalignment of the two shafts. In the event there is any tendency of the shafts to move axially with respect to each other, the forces which otherwise would tend to prevent this movement are dissipated by the sliding movement of the coupling pins 19 in the apertures 31; Thus, the forces resulting from the bias stored in the normally bent rod members act to establish a common or parallel axis for the two rotating shafts so that the two shafts effectively rotate as if they were rigidly connected and disposed on a common axis. Under normal operating conditions, it is desirable to have the complimentary coupling members 7, 9 disposed on the shafts 1, 3 in closely spaced relation thereby to obtain a more rigid coupling for minimizing back lash. However, should the two shafts be considerably misaligned, loading between the shafts and their respective bearings would be increased if the closely spaced relation of the complementary coupling members is maintained. In this event, the adjustable feature of the complementary coupling members will permit repositioning of the members on their respective shafts so that they may be spaced apart a greater distance, thereby extending the effective length of the coupling pin members and increasing the flexibility of the coupling with the result that excess loading is avoided on the shaft bearings.

While the primary purpose of loading or biasing the coupling pin members 19 is to minimize torsional displacement or back lash between the two shafts 1, 3, it serves a secondary purpose in that any wear which is caused by friction between the coupling pin receiving apertures 3l and the coupling pins 19 is taken up so as not to adversely affect the operation of the device over long periods of continued use.

In Figures 1 through 4 of the drawing, the coupling pin members 19 are shown loaded or biased toward the axis of the central aperture 13. However, the coupling pin members 19 may also be loaded away from the axis of the central aperture, as shown by the embodiment illustrated in Figures and 6 of the drawing. In the event it is found desirable to employ an even number of coupling pin members 19, as illustrated by the modification shown in Figure 7 of the drawing, the coupling pin members are arranged to provide duplicate pairs of coupling pin members, with the respective members of each pair disposed diametrically opposite to one another on opposite sides of the collar central aperture. In the event two pairs are provided, one pair can be loaded away from the collar axis and the other pair loaded toward the collar axis, as shown in Figure 7. In all cases, however, it is essential to proper and efficient operation of the flexible coupling that the biasing forces of the coupling pin members be distributed equally about the shaft axis in order to maintain a uniform transfer of driving torque.

From the foregoing, it will be obvious to those persons skilled in the art that I have provided a simple, flexible coupling for efficiently transmitting driving torque between driving and driven shaft members with torsional displacement or back lash held to a minimum, a factor Number While I have described and illustrated three embodi-` ments of my present invention, it will also be recognized that various changes and modifications are possible within the spirit of my invention. Therefore, I desire that the particular forms 0f my invention described herein shall be considered as illustrative and not as limiting.

What is claimed is:

l. A exible coupling for connecting driving and driven shafts in torque transfer relation, said coupling comprising a pair of complementary coupling members, means for releasably securing said members each to a separate one of said shafts, one of said complementary coupling members comprising a rigid collar having a central aperture for receiving one of said shafts, said central aperture having substantially the same diameter as the shaft thereby providing for adjustment of said ,collar along. said shaft, a plurality of resilient rod-like members secured at one of the ends thereof to said collar, said rod-like members being disposed substantially equiangularly about the axis of said central aperture, the other of said complementary coupling members comprising a rigid collar having a central aperture for receiving the other of said shafts, said last mentioned central aperture having substantially the same diameter as the other of said shafts thereby providing for adjustment of said last mentioned collar along said last mentioned shaft, said last mentioned collar being provided with apertures for receiving said resilient rod-like members, the free ends of said resilient rod-like members being slidable within and extending through said member-receiving apertures, said resilient rod-like members being biased in radial directions with respect to said first mentioned axis thereby to engage the walls of said member-receiving apertures and providing the sole means for transferring torque between said collars on said shafts.

2. The invention as set forth in claim l wherein said resilient rod-like members are biased toward the axis of said first mentioned collar central aperture.

3. The invention as set forth in claim 1 wherein said resilient rod-like members are biased away from the axis of said first mentioned collar central aperture.

4. The invention as set forth in claim l wherein said resilient rod-like members are arranged in pairs, the resilient rod-like members of each pair being disposed diametrically opposite to one another, and wherein certain ones of said pairs are biased away from said first mentioned collar central aperture axis, and certain others of said pairs are biased toward said first mentioned collar central aperture axis.

References Cited in the file of this patent UNITED STATES PATENTS Name Date 1,185,208 Lapp May 30, 1916 1,395,289 OLeary Nov. 1, 1921 2,439,479 Mackrnann Apr. 13, 1948 FOREIGN PATENTS Number Country Date 389,907 Great Britain Mar. 30, 1933 398,074 Great Britain Sept. 7, 1933 439,966 Great Britain Dec. 18, 1935 

